Excessive proliferation of fibroblasts???

Two years ago i started takeing HCTZ for hypertension. i was told to take 50mg a day. shortly after that i noticed a growth or swelling of some kind on my right forearm directly over my tendon sheath. i was given claritin and benedryl in case it was an allergic reaction which doctors determined it wasnt. the growth enlarged over the course of 7 months to about 7 inches long running down my forearm starting at my wrist and a inch wide. x-ray and MRI showed nothing there. I had surgery to find out what it was and pathology was " dense fibrosis, does not appear to be malignant" 7 weeks after surgery it was completely back except it wasnt as hard. a year after surgery i had another MRI done because a doctor thought i had soft tissue herniation from the previous surgery which the MRI said that there was no herniation just some scarring in my wrist but still showed nothing where the growth or swelling is on my forearm. A few days ago i saw a doctor for another thing and he said the growth or swelling was probably caused by fibroblasts which repair tissue and excessive proliferation causes fibrosis. Could this be the case? if so any ideas why it started to begin with because i had not injured myself when it initially started. And what should i expect to happen down the road? it didnt start hurting until after surgery and i can see that something is connected to my tendon or tendon sheath because i can see it move when i move my hand. Also i brought up HCTZ because i read a study saying patients who take it for a prolonged time have denser bones because it reacts with osteoblasts, so couldnt it do the same with fibroblast? thank you.